Semiconductor memory devices, including flash memory, typically utilize memory cells to store data as an electrical value, such as an electrical charge or voltage. A flash memory cell, for example, includes a single transistor with a floating gate that is used to store a charge representative of a data value. Flash memory is a non-volatile data storage device that can be electrically erased and reprogrammed. More generally, non-volatile memory (e.g., flash memory, as well as other types of non-volatile memory implemented using any of a variety of technologies) retains stored information even when not powered, as opposed to volatile memory, which requires power to maintain the stored information.
Generally, flash memory devices include a plurality of flash memory die, and each die includes a plurality of memory blocks. In some systems, memory blocks are organized into the metablocks and the memory blocks in each metablock are accessed in parallel to optimize performance. However, the number of useable metablocks may be reduced by the presence of unusable blocks (e.g., blocks that cannot reliably stored data) in the flash memory die, which effectively reduces the amount of useable flash memory blocks by more than the number of unusable blocks.